Field of the Invention
The invention relates to a method for testing a leakage detection system by using a test leak device that is provided with a test leak.
Description of Related Art
When testing or calibrating leakage detection systems used for testing test specimens for leak tightness, test leaks having a specified, known leakage rate are used. The test leak is a component of a test leak device that has a cavity that can be filled with air. The test leak is formed in a wall that surrounds the cavity of the test leak device. Typically, the test specimens consist of the packaging for groceries, pharmaceuticals, or the sterile packaging of objects used in the medical field. The leak detection test is used in order to identify leakages in the packaging that could lead to spoilage of the packaged product. The test specimen that is to be tested for leak tightness has a thin wall that forms the packaging of the product.
The test leak device can be affixed to the outside of the wall of the test specimen, or tested independent of the test specimen.
The leak detection test is performed automatically by using leakage detection systems. Given the background that even small leakages in packaging can lead to the spoilage of the packaged product, the leakage detection systems and the leak detectors must be able to identify small leaks with a high degree of reliability. The leakage detection systems must be tested at regular intervals and if necessary, calibrated. To do so, a test leak is formed in the wall surrounding a leak test device that has a known, specified leakage rate.
Measuring the leakage rate of such a test leak for the purpose of testing a leakage detection system is known. To do so, the cavity of the test leak device is filled with a gas (most often air), and thereby, the test leak is subjected to pressure from the inside. The cavity is designed as a closed volume having a specified and known leakage rate through the test leak. The leakage rate is defined by the reference value of the test leak and by the difference in pressure between the interior pressure within the cavity and the exterior pressure outside of the test leak device. After the cavity of the test leak device has been filled once at the start of the test, the interior pressure of the test leak device decreases from one test to the next test as the result of the gas that escapes during the test. This decrease in pressure increases in direct proportion to the leakage rate and the frequency of using the test leak. As a result, the leakage rate of the test leak device steadily decreases and the test leak device must be refilled manually, or the test leak must be calibrated anew.
The test leak device can be, for example, a test specimen, i.e. a food package or packaging of another type. Alternatively, the test leak device can also be designed separate from the test specimen and, for example, be affixed to a test specimen on the outside.
The invention is based on the objective of proposing an improved method for testing a leakage detection system by using a test leak device that has been provided with a test leak.